First, I ended up with twice the number of raw files, CR2 and dng, and they were eating up space on my systems. Second, I was not crazy about how the files looked when I imported the dng files into LR.

Yes, that was my experience also...

It may not have the range and flexibility of LR but a good case could be made that it is an excellent way to pre-process CR2 files into TIFFs would could then be used directly in LR4.